The present invention disclosed herein relates to a torque transducer, a method for manufacturing the torque transducer, and a transmission for a vehicle using the torque transducer.
In recent years, studies with respect to electronic control systems using a torque transducer are being actively conducted. Torque transducers may be classified into fixing type torque transducers, contact type torque transducers, and non-contact type torque transducers. The fixing type and contact type torque transducers may measure the magnitude of torque by using a strain gauge. On the other hand, the non-contact type torque transducer may be spaced a predetermined distance from a rotation shaft to measure the magnitude of torque by using magnetic fields.
A method for measuring torque of a rotation shaft by using a strain gauge, a slip ring, and a wireless transceiver among the non-contact measuring methods may have a difficulty to be applied for measuring torque of an output shaft in a vehicle driveline. As a result, methods for estimating torque by using an observer or indirectly obtaining torque information by using only a speed single are being studied.
However, these methods may be unsuitable for being used in an extensive operation region due to large estimation or calculation error.
Methods using a magneto-elastic material that actively generates a variation in magnetic field due to a variation in torsion stress as other non-contact measuring methods are being studied. However, a torque transducer using these methods may be difficult to be commercialized because of a relatively high price than those of other sensors and relatively weak durability due to brittle property of the magneto-elastic material.